Inspection device



INSPECTION DEVICE Frederick L. Calhoun and Abner L. Browning, Inglewood, Calif., assignors, by mcsne assignments, f to Geo; J. Meyer Manufacturing Co., Cudahy, Wis., a `corporation Filed Apr. 22, 1959Ser. No. 808,172

21 Claims. 4(Cl. SiS- 14) T his invention relates to apparatus for inspecting bottles for cleanliness and, more particularly, to improvements.

therein.

. 4In an application for a Bottle Inspection System', `Serial` 'No. 741,634, led June l2, 1958 and now abandoned,`

andI assigned to a'co-mmon assignee, 'there is described a novel bottle inspection system of the type -wherein'a't one' l from the light eld. However, instead of simultaneously scanning the entire light tield, which' emanates vfrom a '.bottle'in the inspection zone, means are provided -`for applying light to the reticle from lessthan the entire area or"y the'light tield. Further provision is made tor moving t this means to'cover successive areas of the light field so side a light source, preferably diffused, is provided, and'A at the other side, a photoelectric scanningarrangement is positioned. Bottles lor othertranslucent containers,

which it is "desired to inspcct,.are passed throughthe inis present in the bottle, this is detected at the output'of ln accordance with the invention described in thev above mentioned application,.th e photoelectric scanning means to intercept theflig'ht which is passing through-.the bottle to the photoelectric scanning means. of the bottle is such as. to 'provide what may be caliedya If the illumination 1 t areas of the light iield upon a reticle; ,2Q spection zonedetined by the light source and 'the photo- `z electric scanning arrangement. When a foreign object i the photocell and the bottle-reject operation islinitiated. t

that the reticle will, thereby scan the entire light lieid.

-Th'e-'novel'featurc's that are considered characteristic i of` this invention are set forth with particularity in the 'appended claims. The invention itself, both as to its organization and method of operation, as wellas additional objects and advantages thereof, will best be understood fromll the following ldeseriptitm when read cori-4 `nection with theaccompanying drawings, in which:

. FIGURE l illustrates the type of scan employed by the embodiment of the invention; ,A f FIGUREZ showsone arrangement in accordancewith this'- invention for projecting the light Afrom successive `FIGURE 3 shows lanother arrangement for projecting 'successive areas of a lighteld upon a reticle;

FIGURE ,4 Ishows one embodiment of the invention;

FIGURE 5 shows a'preferredvembodiment of thein'- ventiO'n; and I FIGURE 6 .shows alpreferr'ed arrangement for a Referringnow to FIGURE l, `there maybe seen a reticle or disc-10having alternate opaque 11 and translucent 13-areas thereon. VIn the invention. described'in the -application referred topreviously, the reticle was rotated onits axis, for example, in thedirection indicated field of light, then the'entire field! emanating from the bottle is simultaneously applied to the rotating discfor` reticle. The reticle isl made'up of substantially radially extending alternate opaque and translucent areas.v This `enables the detection oi smaller foreign particles` than 'could be detected'heretofore.

in the bottle, the opaque areas ofthe rotating reti'cle are alternately over the particle covering it and then uncover- For any-foreign particle `-would be. focused upon the reticle.

' by the arrow.. By means of a suitable lens system (not Y shown) 'the'entire vfield of light, represented by the circle 12, emanating from the' bottle which is being inspected Thus, any dirt particle' which is eitherat the center or which overlaps the I t. center substantially equally provides substantially no indi# ing it. 'By covering and: uncovering is meant that an opaque areal is interposed or not between thparticle and photocell. Thereby, the output of the photocellis an alternating-current signal having a frequencybas'icall'y determined by the speed of rotation -o the `retic-le-tin res the number voi spokes.

For a clean bottle, the output of 'the reticle is substantially direct current.

The system described briey above and inthe aforesaidl application `operates successfully to detect smallerforeign` particles than heretofore. However, there are several limitations on the detection capability of such a scanning system, For example, the sensitivityof the scanner at the center of the rotating' reticle is very low, particularly to large, symmetrical objects 'that overlap: the` center.

Furthermore, foreign matter that forms a line lthrough has one value, andati-he next instantthe reticle is moved. s'o that the dirt .particle 'comes under oneof the transthe center of the reticle and several'other positions ofi center provide very poor response. i

An object of the present invention is'l to provide an improved scanning system which eliminates low-sensitivity scanning regions.

Another object of the present invention is the provision -of a novelscanning system which provides a' high response sensitivity,.regardless of the position of vthe dirt in the vlight eld or its shape.-

' Yet. another object ofthe present invention is the provision of a novelk and improved scanning system which' provides a high sensitivity over the entire zone being scanned, regardless of dirtparticle size or shape.

These-and other objects of the invention are achieved in an arrangement where a spoltedV reticle is-positioncd in front of the photoelectric scanner to interceptthe light cation tothe inspectionapparatus. The reason for this Should a dirt particle hep'resent-at locations other than those of the typernentioned, then, at one instant,

the dirt particle' is covered by onev of the opaque areas and'the'light coming `throu'glithe reticle to the photocell lucent areas, whereby the amount of light-is varied from what `it -was' previously. Thus, an alternating-current sign'aiwi-ll be Seen from the output of the photocell. Obviously, aparticlue inthe regionof the center of the 'reticlecauses extremely minor changes in the alternating current signal being derived from the photocell, 'andz thus the system is not particularly sensitive to particles 'falling in the region mentioned.

in accordance `with this invention,l if instead of focus# ing the entire area of the field of light emanating from a bottle onthe reticle, a means vwere provided for preventing all but the light from avportion. of-the area of the light eld from falling upon-the reticle, and then successive arcas are moved past the reticle so that it inspects the entire light-field area, then ythe low, orinserisitive,A

regions previously discussed arev eliminated. This is schematically illustrated in FIGURE l, where the large circle' 12 represents the entire, light field area which is t'o be-inspected. The si-ze of the disc 10 is shown to be much smaller than this'area for thepurpose of illustrating'that only a portion of the light-field area is seen by the; disc at any one time. This need not necessarily be the case, since by means of lenses the lighteld area and .',l,os1,eV Patented Mar. 19,1963

the disc may have any relative size. The opticsselected may provide thc'condition desired as shown in FIGURE l. For the condition shown, the diameter'of the reticle consideration, or only a portion ofthe A'frequencies generated, or to have a shaped frequency response, depending on the nat-ure of the field inspection desired. 4Optiis slightly largerv than the radius of thearea tolbeinspected. Thel reticle 'and light lield are thenrnoved arelativepath, whereby the reticle -is nutated and in one mum signal-to-noise ratio for the system can thus 'be achieved for the entire eld' or any part of it.

` FIGURE 3A showsjan arrangement which maybe subrevolutionthe entire area to be inspected is scanned. The

nutati'ng path 'of -the center of thereticle relative to the light tielcl'isV represented by the dashed circle in FIGURE 1. As indicated, the reticle diameter is slightly larger than the radius of the area to be inspected,l so as 'to have an overlap inthel center to insure adequate coverage.

4The reticle n eed not be rotated as the nutating'motion l occurs, but itis preferred that it does and at a-,higher speedthan the speed of mutation. In this marmer, it is insured that any point in the field is scanned at some time by the more sensitive parts of the reticle. lFurthermore, ,by 'the rotation of the reticle, any pointr in the held is scanned more than-once, and thus positive detection is obtained.

Thejarca scanned .or total light lield 12 which is in-V stituted for the prism. It consists' of apipe 25, .which is hollow and which has'its cylindrical'aitis". offset -frornjthe axis of rotation. The pipe issupported for notation infa mount 24. This, in turn, is` held in a bearing. 26. The

size of the inner" diameter of lthe pipe should'be sutlicent so that the center of the light tield'area being scanned as the pipe rotates is overlapped. Another method, not

shown, is to use a Cassegrainiantype of telescope with atilted-mirror optical' S1/Stem,

vFIGURE 4- is a, more complete arrangement -in accordance with this invention for 'inspecting' a bottle for dirt particles. The inspection z'one may be defined as thev zone which has at one side a means for illuminating the 20 spected, as pointed out above, isdetermined by rotating the smaller Ainstantaneous field dened by the disc or reticle along the dashed line circle, shown in'FIGURE l, at some nutating rateSz. The reticle is alsospun at i preferably a higher rate Sx. Now if both the reticleand' the nutation Imotion are clockwise, as shown in FIGURE l, then the' frequency output across the field is not a con- On the edge of the field 12 the frequency is Srl-NS2. Toward the center the frequency is S-1-NS2. The N is the number of dark spokes in the reticle. For'example, the reticle frequency is 2000 cycles perisecond, the nutation speed iscycles per second, and the reticle has tive light and tive dark I spokes; then, on the nutation circle', the output frequency l.

. stant. On the nutation circle the frequency is essentially the reticlefrequency S1.

ofthe nerd 12,

of which thel 'photocell 36 is supported. A condensing lens 58. focuses the output of the reticle upon the photois 2000zcycles, and-on "the edge of the field IZ'the fre-` Theffrequency output at the center of the field is approximately 2000-(5 20), or 1900 cycles.v Atpositions between the center and the'edge of the field, the frequencies range from 1900 to 2100 cyclespercyl'e.

v lt should now .become'appar'ent that the sensitivity of the field can be shaped so as to enhance the signal output of i any radial beltlin theeld `by adjusting the frequency 'response of the detection apparatus, such as that ofran amplifier following a'pickup phototube (shownkin FIG- J quency `is approximately -ZOOO-l-(S-X 20), or 2100 cycles. i

URE 2). Thus, if such an amplifier is tuned from 1900 cuit noises are rejected. This allows an optimum signalto-noise 'ratio for the system. l

. Although it is possible tonutate the reticle while the light field remainsstationary, a much simpler arrangement for obtaining` the desired result is shown in FIG# URE 2. There, the photocell 1'4 has interposed between it and light emanating from'a bottle'to be inspected a .reticle 16. A The phototube'has its electrical output counected' to a tuned amplifier 15.` 'The amplifier 15 output is applied to the reject mechanism' 17, which operates. in'

the presence of a predetermined'output from the. amplifier 15. Betweenthe'reticle and the light eldifromthe vbottle there isv shown a prism 18. The 'prism has two opposite'faces, onev of which 20 is flat-and the.A other 22 is at an kangle to the flat face. The at face-is 4substantially parallel to the reticle. The prism at, any one instant willonly tgatherlight from.A one of the yareas delineated by the c irclesA, B or C, depending upon the to 2100' cycles, the entire lield is covered,.but'other cir- .i

`while the vbottle 3 4 is'inthe inspection zone.

FIGURE 5 shows a preferred-'arrangement of. the embodlment 'of the invention. The light bulb 30 illuminates the inspection zone. The light from the bulb 30 bottle, such as a light bulb 3 0 and an opal glass 32. The light from the 'bulblpasses 'through the glass, which diffusesv it,and 'thereafter the light passes through the bottle- I .34. The other side of .the inspection zone is the photojeellA scanning. means 36. t

'.Opposite the bottle is a field lens.38, which focuses the vlight iield upon the reticlel 54.. The prismA 4.0 is the same type of-prism as the. one 18, shown and described above in reference'to FIGURE 2. The prism 40and teld lens 38-.are both mounted in a bearing pulley 42. The bearing pulley is mounted in a. bearing 44,'.Which in turn is mounted in `a bearing blockv46. A motor 48vdrives a motorvpulley 50, which in' tturndrives a belt 52. This belt passes' over the bearing pulley 42, 'and thus the prism mounted therein is enabled to be rotated. The retcle 54 i'sm'ountedat one end of alight pipe 5 6, in the other end cell 36. Bothibearir'ig block and light pipe insure that.

no extraneous light. will reach the photocell. In the embodinient ofV the invention shown in FIGURE '4, the. ret-A lcleus maintained 'stationary and the prism', 40 is rotated rapidly toinsure several scans of the entire'light-eld area 'passes through. 'the opal glass 32, and then through the bottle 34. The. eld lens 38 focuses the light from the light eldupon'the reticle v54. The p'risrnA operates in the manner described to transmit the lightfrom a portion -of .the entire area of the light field to the reticle 54.

'The tield lens and prism are mounted in a bearing pul. ley- 42. The bearing pulley is mounted in a bearing 44,

` which in. turn iis mounted in a bearing block 46. The

1 tion-of the light 'pipe and'reticle. A condensing lens 58' I focuses the hght from the reticle 54 upon the photoinstantaneous position of the prism. Only the light from the delineated area Vwill be enabled to -fall upon the 4reticle 16. Accordingly, by rotating the'prism 20, it'successively permits light from a ditierent area ofthe lighteld to fallupon the reticle, -whereby the reticle may scan the entire light held. The amplier 1S is tuned to am- "plify either all the `frequencies generated by `the combined 'disc and prism rotations, taltingthereticle markings into reticle 54 is supported in alight pipe 60. The light pipe,

Vin turn, is rotatably mounted in a bearing 62, whichin turn` is. supported from a bearing block' 64. A pulley 66 at one end of the light pipe 60 is used to enable the rota the. pulley 42, for the purpose of rotatingthep'rism, In

view ofthesize's of the pulleys, theretcle will be rotated at a speed which is higher than the speed of rotation of the prism.V AAs the prism assembly rotates, theA projected eldzis also rotated at. the lsarde speed, thus givingthe .desired mutation etect. Itv should be. noted that although the nutation illustratedherein isi-circular in form, lthis should not 'becon'sideredasa restriction, since `with dif.

5 ferent lenses and/or mirrors which can be employed, other types of iield scanning may be employed;

tive -to the bottle for sequentially scanning progressive i arcas ofthe bottle to pass the energy from such progres- The pattern of alternate translucent and opaque areas on the reticle should be optimized, morder-to eliminate any null positions in the field. This can be accomplished if'the reticle is designed so'that the object in the field always crosses severalv of the radial spokes, regardless of the objects position in the fieldA The spot provided by the' Aobject must'` passover opaque -andclear areas in order to obtain the light variationsnecessary. 'The resulting frequency of vthe output variation should `xbe as constant as possible. v Y- Reference is now made to FIGURE`6, which illustrates one type of optimized pattern arrangement.' The reticle 80 has the alternate light and dark areas' disposedY in concentric ringsand the radially extending light and dark areas are also alternated,

There has been accordingly shown and described herein a novel, useful arrangement for increasing the accuracy of an inspection system and for also eliminating any posi-A tions within the field of inspection which Ibecause, of their location relative-to ythe retcle being employed caused the apparatus to be insensitive. This invention enables the detection of anycontrast in an otherwise homogenous field being inspected.

`We claim: l. In a system for inspecting-a bottle from theybo'ttle for modulating the energy from the bottle to obtain the passage from'the modulating means 'of energy'having direct characteristics upon the lack of Oef".` cur'rence of a foreign particle vin the bottle and having characteristics alternating at a particular frequency-inf accordance with the occurrence of foreignl particles in the bottle and in accordance .with the .characteristics of the scan, means disposed relative to the modulating means v for foreign partii cles, means disposed relative to 4the 'bottle for directing energy toward the bottle, means .responsive to the energy sive areas at successive instants of time where the energy is substantially constant at the successive instants of ltime upon the lack of occurrence of a foreign particle l in the bottle and where the energy has alternating characteristiesv upon Ithe occurrence of a foreign particle in the bottle, and means responsive to the alternating'energy passing from the scanning means upon the occurrence of a foreign particle in-the bottle for producing signals h avi the position of a particle ing .characteristics representing inthebottle. i t 4.. In 'a system for inspecting a bottle for particles o f Vforeign matter, means disposed relative to the bottle for directing energy toward the bottle, means disposed rela'F tive to the `bottlefor sequentially modulating the energy 4from the bottle to obtain the' passage from the modulating means of energy having substantially constant characteristics-upon the lack of occurrence of a foreign particle in the --bottle and having characteristics alternating at a' frequencyrelated to the operation of the modulating t `means andldependent upon the'occurrence of aparticle in the` bottle and dependent upon the position of the particle in the bottle, and means responsive to the alternating energy passing from themodulating means `for producing electrical signals having a frequency-related tothe frequency in thealternations in the energy from the modulatingy means to provide an indication .as to the position' ofV the foreign particle in the bottle.

5. Inya systemfor inspecting a container for particles of foreign matter, a source-disposed relative to the con- .ltainer foripdirecting energy toward thecont'ainer, nutatmg means disposed relative to the container for passing enfor obtaining a sca'n by the modulating means' oftheenj v ergy from-progressive areas of the bottleat successive 'instants of time where each progressive area extendsffrom lthe periphery of the bottle pastthe center of the bottle and includes the `center ofy Athe bottle and a progressive distance along the periphery of the bottle, means responsive to the energy passing from the modulating means at successive instants of time for producing signals in accordance with such energy and having alternating'characteristics and representative of any -foreign particles in v the bottle, and means responsive to the alternating signals ergyfrom thecontainer at progressive areas of lthe con# i tainer and at successive instants of time 'where veach progressive area has a' length greater than one-half ofthe length of the 'container to provide an overlap inthe pro- U Vgre'ssive areas; and means' response to the signals from' the signal means for providing a direct signal representing a lack of occurrence of a foreign particle in the con- V tainer an'dfor providing an alternating signal representing the occurrence for a'foreign particle-:inthe-container.

' 6.v In'ari inspection systemrfor detecting foreign parti-` cles in 'a container, means disposed relative to the' container for' illuminating the container to provide a field forinspection, means disposed relative tothe .container for scanningthe entire field and including a continuously rot-ating'optical member 'for sequentially scanning dif- 1 ferent areas which together comprise the field, each of the extended areas scanned at any instant being substantially larger `than the size of the foreign particles to lne-detected and having a length greater 4than one-half of the length ofthe iield, .and means disposed 'relativeto the scanning means-and responsive to the light from said opticalmember for converting such light to a direct signal in response to a' lack of occurrence of a foreign particle in the conlap to obtain a complete scan of the bottle; and where each of the progressive 4areas extends from the periphery of the bottle past the center of the bottle, meansdisposed relative to thelast-mentioned means for modulating the energy 'passing from the last-mentioned means to obtain the 'production of a substantially constant energy upon the lack of occurrence of a foreign particle in the bottle and to obtain the production of alternationsat a particular frequency in such energy in accordance with the oc- 1 currence of a foreign particle in the body, and means responsive only to the alternatons at the particular frequency in the energy from the last-mentioned' means' for providing an output indication representing the occurrence of aforeignparticle in thebody.

3. In a system for inspecting a bottle for particles of foreign matter, means disposed relative to the bottle for directing energy toward the bottle, means disposed relabottle, photocell means disposed relative to the disc forftainer and for converting such light lto an. alternating sig'- nal in response to the presence of a particle in the container.

7. In a system for inspecting a bottle for dirt and including means for illuminating the bottle, the improvement including: a disc having alternate opaque and'translucentareas, means operatively coupled to the di sc for supporting said disc in a position to intercept light passing from said bottle, meansfor directing upon said disc the light from an area of said bottle which is. smaller than the entire area ofsaid bottle and whichextends beyond the center of said bottle from the periphery of the producing signals in accordanceyvith the light passing throughthe disc, circuit means operatively coupledto the photocell means for producing a substantially constant signal 'in the absence of dirt-in the bottle and for producin'g an alternating signal upon the occurrenceofVV dirt in the bottle, and means for moving said means for directing to sequentially direct light 7 c from progressive areas of the bottle 'upon s aid disc until said entire bottle has been scanned by said discwhereby light from the center of the bottle is provided along a circular path across said disc.

8.olnV a system as recited in claim 7 wherein said means'for directing light from lessthan thev entire area of said `bottle upon said disc 4comprises aV cylindrical prism having two faces','oneface being substantially parallel to said disc and the other face being at an angle tosaid one face. l

9. "In a system as recited in claim 7 wherein said means for directing light from less than the entirearea of said bottlerupo'n said disc comprises' a hollow cylinder, and

means for supporting' said hollow cylinder between said l0. In a system as recited in claim 7 whereinzisaid disc has alternate opaque and translucent areas disposed vin concentric rings and alternating radially as well as within said concentric rings.

ll. In a system as recited in claim 7 wherein said means for suppoiting said disc includes means for rotating 'said disc through a plurality of revolutions-within thel time of directing the light from the entire bottle upon said disc by said means for directing- 12. In a systemfor inspecting a ment including: alight chopper having alternate translucent and opa'que areas, means operatively coupled to thelight chopper for supporting said light chopper in a position to interceptfthe light passing from said bottle, meansfo'r directing upon said light chopper light from a -8 i "15.111 a system as recited in' light chopper is a disc having its alternate opaque vand translucent areas disposed in concentric rings and alternatxng radially as well as within said concentric rings.

t ""16. 1n a system for inspectinga bottle'for dirt and including means forilluminating the bottle,- the improvement including: a photocell, alight chopper havingalter.- l

nate translucent andzopaque areas and disposed between the bottle and the photocell, .means 4operatively coupled to the light chopper forrotatably supporting said light chopper in `a position to intercept light passing from said botvtle to said pl1otoc'ell,`meansv including. a prism disposed between. the-.bottle and the light lchopper 'for direetin'grthe disc and bottle for .rotation with its axis at 'an angle to the axis of rotation.

light vfrom less than the entire area of said bottle upon said lightchopper, means operatively-coupled vto said prism for rotatably supporting said prism to obtain a 4rotation "of-the prism about the same axis ofrotation as that 'oi said light chopper, means operatively coupled to -the light chopper and the prism for rotating said light chopper and said prism and for rotating the light chopper at -a speed different from that of said prism, and an aml bottle for dirt Aand i yincluding means for illuminating the bottle, the improveparticular portion of said bottle including' a prism positioned between said bottle and said light chopper and `having 'one face parallel to said light choppery and aseomeans for producing a'direct signal in the absence of dirt in the bottle and for producing an alternating signal upon the occurrence of dirt inthe bottle 'to provide an indication as to the presence of dirt in the bottle. v

13. In a system for inspecting abottle for dirt as recited in claim 12 wherein said means for supporting said` light chopper includes means for rotating said light chopper on the same axis of rotation as-that of said prism and at a different relative speed. v.

14. ln *a system for inspecting a bottle for. dirt and defined by means for illuminating the bottleithe improvement comprising a light-chopper having alternate translucent and opaque areas, means for supporting said light chopper in'a position to intercept the light passing from said bottle, means for directing the light from less than the entirearea of said bottleupon said light -chopper including a prism positioned between said bottle and said light chopper'and having one face parallel to said' light chopper and an opposite face at an angle to said one face, means'operatively coupled tothe prism for rotatably sup-l porting s aid prism for rotation about the same axis o f rotation'as that of said light chopper, and means operatively coupled to saidV light-chopper and said prism for rotating said light chopper and -said prism and for rotating said light chopper at a diilerent speed than said prism, photoelectric means disposed relative-to the -light chopper l for inspecting the light passing through said chopper, and means operatively coupled to the photoelectric means for producing a direct signal inthe absence of dirt in the bottle and for producingan alternating signal upon the occurrence of dirt in the bottle.

`plitier connected to receive said photocell output, said vamplifierincludingl means for tuning the amplifier to reject -direct signals representing the absence of 'dirt in the bottle and respond to particular frequencies in the output of saidphotocell for providing an indication as to the presence of dirt in the `bottle and asl to the position of the dirtin the bottle.-

17. A bottle inspection system for indicating'the pres- 'ence ofa foreign particle in a bottle, comprising, means for illuminating a bottle with light, scanning means constr ucted and disposed relative to the bottle to pass light `of:substantially 'constant intensity-upon the lack of 'occur- `rence of a foreign particle in the bottle and to pass light of varying intensity upon the occurrence of a foreign particle in the bottle, said scanning means includinga member having alternate opaque 'and translucent areas and-a cylindrical prism rotatably mounted between said bottleand said member, means for rotating said prism to successively direct light from dilerent areas of the bottle upon said 'member until the entire light ield has been Scanned by said member, photoelectric means constructed vand disposed relative to said scanning means to receive light from said scanning means and to render 'a substantially constant signal output when receiving light of constant intensity and to render avarying signal output when receiving light of varying intensity, and an inspection circuit means responsive tothe output from said-photoelectric means and constructed to pass a bottle when -a substantially constant signalis received and'to reject a bottle when a varying signal is received from said photoelectric means.

18; In 'an inspection System for detecting foreign par- '.ticlesin la container, means disposed relative Vto the container for illuminating the container for inspection, means disposed relative to the container and the illuminatingmeans for." sequentially directing vlight from different areas of the"illurninated container as a vbeam along a particular path, where each of the `diierent instantaneous areas 'extends beyond the center of the container and where the different areas together cover the entire container, .and vmeans including photocell means positioned in the particular path of the beam of directed light for converting light from only predetermined portions of thebeam to electrical' signals and for generatingA a direct signal in response to a lack of occurrence of a foreign particle in the container and for generating au alternating signal in response to the presence of a foreign particle in the container. w

19. In an inspection system for detecting foreign particles in a container, means disposed relative to the container for illuminating the container for inspection, meansdisposed relative to the container for cyclically and sequentially scanning the light passing from proclaim 14 wherein said gressive extended areas 'of foreign particle in thecontainer.

the container where the i electric means upon extended areaof the vcontainer 4at any instant-extends from the periphery of the container to' a position beyond the center of the containerand is substantially greater than the size 'of the foreign particles to be dctected,and

means responsive to the' light scannedby the scanning -meansfor converting the light from the diierent extended areas of the container-to a direct signal upon the lack ot occurrence of a foreign particle in the container and 10' to an alternating electric signal upon the vpresence of a 20.. In a system for inspecting a bottle Vfor particles Vof dirt, includingmeansdisposed 4relative to theV bottle fr om the beam to'electrical signals and fgor generating a' dn-ect `signal in responsej to the absence of a foreign for' illuminating thebottle to provide alig'ht eld' for inspection, photoelectric means disposed relative -to the bottle for converting the light from 4the `bottle to elec- 4trical signals having characteristics dependentuponthe light directed'tothe photoelectric means, a stationary disc positioned in front of-sad photoelectric means for intercepting light directed to said photoelectric means, said disc having alternate' transparent and opaque areas supported in front of the photocell means so 'that only -...c 1u des -thejce'nter of the containerand progressive portions of the periphery of the container, 'and third means including I photocell means positionedm theparticular pathof the beam of directed light for converting vlight particle' in the container and for generating anv alternating signal in response .to tbe presence of a foreign particle `in rthe transparent container, said second. means includparticular portions -of the light directed to said disc ingto said disc light. from an extended area ofthe light field which is substantially larger .than anyparticles of dirt in the bottle and'smaller thanthe .entire area 'of the field and 'which extends beyond the center of the bottle,

and'means for moving said directing-means to seque'n` tially direct light from successive extended areas ofsaid light eld until the scanning of the entire lighteld'by impinges upon said photoelectric means, means for direct- 25 said stationary disc to obtain the production of a direct" signal by the photoelectric means uponthe lack of occurs rence ofa foreign particle inthe bottle` and to obtain the .production of an alternating signalby thephoto.-

ing aIOtatable prism positioned between said container and," said photocell means and constructed to produce 'a movement ofsaid bearn with respect to said -photocell meansin Iaccordance with the rotary movements of the prismand further including lmeans operatively coupled Vto -the prism for obtaining a rotary movement ofthe Prism.

References' Cited in the tileof this patent UNITED srArEsPATENTs l s Ives .r ..2 Nov. .1, 1927 2,016,036 Fitz Gerald oct. 1., :1935 2,265,037 Guuiksen Dec. 2, 1941 2,431,510 Salinger s. Nov. 25, 1947 2,946,893 Baum 2-2 July 26, 1960 FOREIGN PATENTS -Great Britain' Apr. i2, 195o4 

1. IN A SYSTEM FOR INSPECTING A BOTTLE FOR FOREIGN PARTICLES, MEANS DISPOSED RELATIVE TO THE BOTTLE FOR DIRECTING ENERGY TOWARD THE BOTTLE, MEANS RESPONSIVE TO THE ENERGY FROM THE BOTTLE FOR MODULATING THE ENERGY FROM THE BOTTLE TO OBTAIN THE PASSAGE FROM THE MODULATING MEANS OF ENERGY HAVING DIRECT CHARACTERISTICS UPON THE LACK OF OCCURRENCE OF A FOREIGN PARTICLE IN THE BOTTLE AND HAVING CHARACTERISTICS ALTERNATING AT A PARTICULAR FREQUENCY IN ACCORDANCE WITH THE OCCURRENCE OF FOREIGN PARTICLES IN THE BOTTLE AND IN ACCORDANCE WITH THE CHARACTERISTICS OF THE SCAN, MEANS DISPOSED RELATIVE TO THE MODULATING MEANS FOR OBTAINING A SCAN BY THE MODULATING MEANS OF THE ENERGY FROM PROGRESSIVE AREAS OF THE BOTTLE AT SUCCESSIVE INSTANTS OF TIME WHERE EACH PROGRESSIVE AREA EXTENDS FROM 